<div class="context">
  填空:第{{ data.studentAns.titleNumber }}题
  <mat-form-field
    *ngFor="let item of studentAnsArray; index as i"
    class="blank-field"
    color="accent"
  >
    <span matPrefix> 第{{ i + 1 }}空 &nbsp; </span
    ><input
      matInput
      placeholder="填写答案"
      class="input-ans"
      [(ngModel)]="ans[i]"
    />
  </mat-form-field>
</div>
